Pursuing Differentiated Services in a SDN-Based IoT-Oriented Pub/Sub System

Software-defined networking (SDN) is a promising future network architecture which introduces new dimensionsin flexibility and adaptability to cope with different Quality of service (QoS) metrics, such as latency constraint, loss rate, etc. In this paper, we provide differentiated Services for flows of a topic-oriented publish/subscribe system to address some of the QoS guarantee issues, by leveraging multi-priority queue functions of SDN. Flows are bifurcated into multi-priority queues in terms of packet properties such as delay and reliability requirements. An active feedback-based queue management mechanism is responsible for ensuring bounded queueing delays for those higher priority queues, and a mapping method accounts for mapping time-constrained flows to different priority queues. The Experiments verify the effectiveness of the queue mechanism and flow scheduling.